How Big a Bounce

With the summer speculation season about to give way to actual running mate picks and the national conventions, it's a fair time to ask how ...

With the summer speculation season about to give way to actual running mate picks and the national conventions, it's a fair time to ask how much effect these events are likely to have in the polls. After all the build-up, the answer is probably not much.

Don't get me started about how much ink and airtime gets devoted/wasted quadrennially gaming out the VP picks. The guesses are typically wrong and then the running mates are all but forgotten as they spend weeks out on the B-list hustings.

As for the conventions, obviously they are less important and dramatic in the past and consequentially receive less coverage. But they still draw a lot of attention and set the stage and themes for the fall sprint to the finish.

They don't, however, give the candidates as big a bounce as commonly expected. Karlyn Bowman, resident polling guru at the American Enterprise Institute, has gone back and collated the polling data before and after recent conventions.

Some candidates get almost no bounce. In 2004, Bush get a two-point bump, while Kerry's numbers actually went down (sign of things to come for him). Others who got bounces went on to lose, including Goldwater, McGovern, Mondale, Dukakis and Carter in 1980.

Bill Clinton fared best, says the AEI press release:

Bill Clinton received a sixteen-point bounce after the 1992 convention, according to Gallup. The CBS News/The New York Times pollsters and the NBC News/The Wall Street Journal team credited him with twelve percentage points. This is by far the largest convention bounce in modern history.

What this doesn't note is that during the Democrats' convention that Ross Perot dropped out, temporarily, with much of his support switching over to Clinton as the out-party candidate.

I will admit I'm curious how the conventions play, of course, and whether they move the mostly stagnant poll numbers for either candidate, especially in a back-to-back scenario like we'll be having.